1. Field of the Invention
This invention relates generally to a compact apparatus for grooving a tube and a method for grooving a tube.
2. Description of Related Art
The need for grooving a tube is generally known in the art of tube coupling and tube repair. Victaulic couplings are used in making joints, retrofits and repairs in tubing, both in-situ and otherwise, and require grooved tubes. A Victaulic seal is especially useful for fitting copper pipes together, in all sizes of pipe, since the seal does not use heat which can unevenly expand the pipe ends used in the repair. It is extremely difficult to form a good seal between unevenly expanded pipe ends. Moreover, a method for sealing pipes that does not require heat is safer where combustible materials are present.
To make a typical Victaulic coupling, a groove is formed around each end of a pipe. The two ends of pipe are then lined up and a rubber ring is fitted around the joint. Two semicircular bands, forming a sleeve, each of which have a ridge on both edges to fit into the groove of the pipe, are placed around the ring and are drawn together with two bolts. As the bolts are tightened, the rubber ring is compressed, making a watertight joint, while the ridges fitting in the grooves make the joint strong mechanically. In fact, as the pipe hydraulically expands, the pressure tightens the bolt, making the Victaulic coupling repair even stronger.
A tube machine is shown in U.S. Pat. No. 3,362,212 issued Jan. 9, 1968 to Steele. It describes a machine for tapering the end of a tube, bolted to a base or table and attached to a power source, thereby requiring operations to be at the site of the machine.
U.S. Pat. No. 5,799,531, issued Sep. 1, 1998 to Orcutt et al., describes a crimper fitting locator assembly. The described assembly has a hydraulic ram actuator assembly affixed to a bed plate with columns and a locating assembly mounted on a support.
An automatic crimper and crimping die is shown in U.S. Pat. No. 4,703,643 issued Nov. 3, 1987 to Brooks et al., which requires that the length of a stroke of a ram against crimping dies is controlled electrically by comparing voltages on a balancing circuit.
U.S. Pat. No. 3,217,519, issued Nov. 16, 1965 to Demler describes a coaxial crimping tool. The tool is for coaxial cable, and requires that the cable be stripped and otherwise prepared before crimping. Also, there is no adjustability of the stop pin.
Rollers are also known in the art of grooving tubes. However, rollers are expensive machines and are bulky. Generally, they require the pipes to be of a minimum size for optimum use. Furthermore, they cannot be used in in-situ repairs.
The invention is a compact apparatus and a method for grooving a tube. The apparatus would typically be used in the field, although it may also be used in a workshop, laboratory or other location.
The invention has a stud with a partitioning ring, a mandrel, a plurality of jaws and a tightening mechanism. The mandrel is fitted around the far end of the stud through a hole on the center of the mandrel. The mandrel has a far end with a resting place for a tube to be worked. On the near end, the mandrel has a recession complementary to the partitioning ring. The tube may be grooved in-situ; however, it may also be worked away from where it is placed.
A plurality of jaws is placed around the mandrel. The jaws have protrusions on their interior surface on their near ends that are complementary to a groove around the near end of the mandrel. The jaws also have flanges on their interior surfaces on the far end for providing the grooving on the tube to be worked.
A tapered sleeve is then placed over the near end of the stud. A tightening mechanism is placed behind the tapered sleeve on the near end of the stud. The tube to be worked is then fitted over the far end of the mandrel, resting on the resting place. As the tightening mechanism is tightened, the interior surface of the tapered sleeve interacts with the outer surface of the jaws, and the sleeve is drawn toward the mandrel. Thus, the flanges on the jaws form a groove on the tube.
In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.
The prior art fails to teach a compact apparatus for the grooving of a tube such as a metal pipe. The prior art also fails to teach a compact method for in-situ repairs where there is little clearance of the pipe. In addition, the prior art fails to teach a method that is ideal for cosmetic and structurally sound Victaulic couplings, with manual control of the grooving mechanism.